My 98.5 still lets out a noticeable black puff and is real doggy out of the hole.

I’ve done all the obvious, checked boots, pressure test, exhaust manifold and disconnected the EZ. This became evident on the first run after a block swap (53) about 18 months ago.

I was leaning toward the VP. Original with 160K but this seems like an air problem even though I’ve got good boost. Wastegate actuator line capped at turbo outlet because of leaky actuator diaphragm. Also checked the Wastegate. All free and snaps back to closed no problem.

It drives like a real bad boost leak for about 3 seconds but I don’t have one.

Any ideas? Would a bad IAT or MAP mess things up like this? No codes to date other than (and this might be a clue) P0237 turbo boost sensor low. Ok, so it’s low….why?

Haven’t seen that code for about a year since I cleared it. Other than the intermittent hard hot start (yah I know, VP ) all is running well.

 

u might need a new map sensor

 

Try plugging the EZ back in and disconnect the MAP from he block leave hooked to the EZ. see it that makes a difference. You will get the low boost code when the MAP is unplugged.